Apparatus for sealing glass tubes



June 12,

W. O. LUERTZING APPARATUS FOR SEALING GLASS TUBES Filed May 2o, 194s 2 Sheets-Sheet 1 June 12, 1945.

'w. o. LUER'rzlNG' APPARATUS FOR SEALING GLASS TUBES Filed May 20`, 1943 v2 Sheets-Sheet 2 IN V EN TOR.

Nestea June 12, 194s `'uN1TED-j lSTATE s PATENT OFFICE Arrmrus Fon ssamm Glass 'runas Walter 0. Luertx'lng, E. Machlett Son, tion of New York N. J., assigner to Vineland New York, N. Y., a corpora- Appllcation Ml! 20, 1943, Serial No. 487,731

l tially dat and lies in a plane which may extend at an angle to the axis of the tube. The apparatus of the invention-may be used. for cutting and sealing tubes as such, tubular extensions or necks of vessels, and various'other hollow glass objects, but since the invention may be employed to especial advantage in the production of inclinometers, its application for that purpose will be-illustrated and described in detail by way of explanation.y

Inclinometers, now used'as part of turn and bank indicators for airplanes, include a sealed Glass tube which is curved and contains a'ball immersedv iny oil. The tube is mounted in the instrument with its concave side uppermost and, when the plane is in straight flight on an even keel or is making a turnv with proper bank, the

s cunas. Cl. 4in-'1) menester-.clamping the tube and rotating the clamp and tube in such manner that the Vaxis of rotation passes through the central plane of the desired closure of the tube and extends normal to that plane. Associated with the rotary clamp are burner means by which a thin planar flame may be directed against the surface of the tube lball lies centrally /of the tube at the lowest point se that they will ne vertical m the device' as installed. Also, the tube is provided with a tubulation to permit the oil to beintroduced and sealed in and the tubulation'must extend upward from the concave surface of the tube near one end with its axis radial.

' Inclinometers have heretofore been made by hand and, by manual operations, it is extremely diflicult to' cut and seal the curved tube at its ends with closures which meet the specified re- 'f quirements. Because of such diiliculties, the

manufacture of the devices by hand is expensive not only because of the labor required for production and testing but also because of the large proportion of devices rejected as unsatisfactory.

The present invention is, accordingly. directed to the provision of an apparatus by whicha glass rtube may be cut accurately to length and sealed at its ends with closures lying at selected angles, such as an oblique angle, to the axis of the tube. By the use of the invention, incllnometers of the construction and limitations previously mentioned can be made rapidly and accurately and with substantial savings not only in, actual cost The `apparatus of the invention I comprises along the line where the plane of the desired` closure cuts the tube wall and the burner and clamped tube'may be moved relative to one another in a direction lengthwise of the tube iny order to complete the sealing, as will be presently described. 'I'he apparatus includes other features which simplify its use and insure productionof an acceptable product.

For a better understanding of the invention, reference may be'had to the acompanying drawings in which Fig. l is a view of theI apparatus in side ele-l vation;

Fig, 2 is a plan view of the apparatus;

Fig. 3 is a fragmentary sectional view on the line 3-'3 of Fig. 2;

Fig. 4 is an end View of the complete assembly shown in Fig.3;

Fig. 5 is a view in side elevation with parts broken away of a modified clamp; and

Fig.j6 is a plan view of thefeatures shown in Fig. 5. e

As shown in the drawings, the apparatus as .illustrated comprisesl a motor I0 mounted ina support' II on a base I2. the support. illustrated being-so constructed that the motor shaft I3 lies at an angle to the horizontal with its free end higher. The motor is controlled by a switch vI4. mounted on the base and has a pulley I5 on its shaft about which is entrained a belt I6. The belt drives a pulley I1 cna shaft I8 mounted in bearings I9 in standardsv 20 attached to the base. The standards are soconstructed thatthe shaft Iilextends at an angle to the horizontal-:similar to the angle of-'the motor shaft, and the-standards are capable of adjustment ,so as to vary the angle of shaft Il toua limited extent. The pulley I'I lies between the bearings I9 and it has a groove lfor the belt I6 and a wide face at one side of the groove,so that it can be rotated by hand,

`when desired.

The shaft I l is provided at one end with a crank 2|. from the end of which extends a second shaft 22 lying parallel to shaft I8 and offset'therefrom. Attached to the free end of the second shaft 22 by a bolt 23 is a clamp generally designated 24. `The clamp includes, a central bar 25 secured to shaft 22 by the vbolt and' provided with a pair of lateral bosses 28, to the ends of which av plate 21 is rigidly held by bolts 28 threaded through the plate and the bosses and into plate 25. The plate extends upward above the top surface of the iban; -and serves as one jaw of the clamp. i

Threaded into the opposite face of bar are a pair of studs 29 which have threaded ends-extending loosely through openings in a plate 30 generally similar to plate 21. The studsk are pro vided with nuts and washers 3| on their outer ends beyond the plate 30. A bolt 32 with a fingerV plate 33 at its outer end is threaded through plate 30 to bear against the side of bar 25 and by manipulation of the bolt, the plate 30 may be tilted on the studs so that the upper edge of the plate approaches or recedes from the plate 21. The top surface of the bar 25 is curved toconform to 'the curvature of the tube to be cut and sealed and, when such a tube is seated on the bar, it may-be clamped between the plates 21 ind 30, as' above described.

The tubes to be formed into inclinometers are of the shape indicated at 34, each tube having a curved `central portion and pointed ends 35. In

the preparation of the tubes, they are cut from lengths of tubing and pointed and bent as shown. Thereafter, a mark is placed on each tube to indicate one place where it is to be cut and sealed.

The pointed tube is then placed in the clamp and a gauge 36, which is pivoted on plate 21, is swung outward beyond the free end of the clamp and the tube adjusted so'that the mark is aligned with the end` of the gauge. The tube is then clamped in this position, after which the gauge is swung back out of the way and to the position shown in Fig. 3.

The heating of the tube for cutting and sealing purposes is effected by burner means by which a planar flame is directed on the tube. This burner means comprises a pair of burners 31 which are inclined toward one another so that the flames issuing therefrom impinge on one another and produce the thin flat flame desired. The burners are supplied with a mixture of oxygen and combustible gas through a manifold 38 mounted on the end of a tube 39, which is supported in a sleeve 40 attached to a bar 4| clamped in a support 42. The tube 39 is provided with collars 43 and 44 lying on opposite sides of the sleeve 40 and a spring 45 encircling the tube bears against sleeve 40 and collar 44 and holds the tube with collar 43 bearing snugly against the sleeve 4U. The tube 39 is provided with a T 46 to which supplies o f gas and oxygen are delivered through tubes 41, 48,-respectively.

The tube 39 is provided with a collar 49 between eollar 43 and manifold 38 and a pair of rods 50, 5| are mounted inv collar 49. Rod 50 is acted on by a spring `52 secured to the end of the rod and to a fixed part of the base, while rod 5| is connected by'a link 53 to a crank 54 on a shaft 55 mounted in a bearing on a suitable bracket 56 on the base. with a pair of diametrical arms 51 having screws 58 in their vends and, when the shaft is rocked, one or the other of the screws strikes the base l2 and limits the rocking movement. Shaft 55 is also provided with a crank arm 59. by which the shaft can be rocked and when the shaft is thus swung by arm 59 against the actionl of spring 52, it acts through link 53 to swingv collar49, manifold 38, and burners 31 to shift the plane of the flame issuing from the burners to a slight extent in a direction lengthwise of the tube.

In the use of the apparatus, the operator places the tube 34 inclamp 24, centering the tube by- The shaft is providedabout the axis of bolt 23 so that the axis of shaft |8,.which is the axis of rotation, passes through the center of the plane of the desired closure of the tube and is normal to that plane. With the parts in this condition, the burners are turned up and the motor is started to cause the tube to be rapidly rotated while the thin, flat flame from the burners strikes the outside of the tube. In the initial heating the burners are tilted clockwise by the action of spring 52 and the name, the plane of which is indicated by the dotted line 60, strikes the outside of the tube along the line where the plane of the tube closure intersects the wall. When the tube has been heated so that the glass hasI become plastic along the line of heating, the motor is stopped and pulley I1 is rotated slowly by hand while the heating continues.

When thev tube has been heated to the desired extent, the operator pulls out the pointed end of the tube to the right of the name, as shown in Fig. 1, and in this operation, the softened glass walls draw together' in the plane of the name. y

Thereafter, the burner is shifted slightly to the left by depression of arm 59 and the motor is started again. The tilting of the burner causes the plane of the flame to shift to the position indicated by the dotted line 6|, so that the end of the tube is heated slightly inward from the plane of the cut. As the heating and revolution of the tube continue, the glass from the tube wall runs together to form a flat closure which seals the end of the tube and is of uniform thickness equal to that of the tube wall. The flame helps keep the closure nat and by revolving the tube at the proper speed, the softened glass is kept from being drawn outward centrifugally. When the closure is finished, the arm 59 is released and the burners are turned down. The clamp is then opened and the tube, now sealed at one end, is transferred to the operator who applies a tubulation 62.

The tubulation is attached by usual glass blow ing methods to the side of the tube adjacent the previously sealed end and thereafter, the tube is returned to the sealing apparatus. A ball 63 is then inserted in the tube through its open end and the tube is again mounted in a clamp and its open end cut and sealed in the manner previously described. The clamp used in the second operation is generally similar to that previously described, except that the rigid plate 64, corresponding to plate 21, is provided with a gauge plate 65 which extends across the lower end of the clamp. `When the tube is placed in the clamp with its sealed end abutting plate 65, it lies in proper relation to the flame to insure that the other end of the tube will be cut and sealed at the desired place. After the second sealing operation has been completed, the tube is transferred to the operator who introduces the oil through the tubulation and then seals the latter by customary methods. v

The apparatus described is constructed especially for the production of inclinometers and, for that reason, the motor and shaft I8 are mounted at an angle to the horizontal, so that, when a tube, sealed at one .end and containing a ball, is placed in the clamp against plate 65, the ball will lie at the lower end of the tube against the sealed end and will not interfere with the sealing and closing of the other end. If the apparatus were to be employed for other purposes, the motor and shaft I8 might be mounted at an angle to the horizontal for convenience, but ordinarily the motor and shaft would be mounted intended to' apply 'flame along the 'clamped tube.Y l..

3. An apparatus 'for cutting a glass tubev between its ends and sealing the'tube atthe .cut with in such position that the plane' onwhich the tube is cutwould be vertical, since'this would facilitate the inward flowing ofA the v.molten glass to form the end'wall and complete the seal. The clamp illustrated and'described is constructed 'for use, i'n sealing tubes `of-.a particular size and curvature. As will be apparent, the ap- ,paratus is not limited `in its utility to operation on tubes of a particular type but for handling tubes of other than the curved. shape shown or glass objects of other' shapes, appropriate changes in the clamping means and it's mounting may be .necessary The apparatus .of the invention may be' employed in the cuttingand sealing' .of hollow glass j articles of various types and such articles may have the form of tubes, tubulations or necks of vessels, andL other shapes. For convenience, I have identified .such articles in 'the appended claims as tube's, but it is to be understood that this term is not 'limited to tubes as 'such but is to other hollow glass objects,

l. An apparatus for cutting a glass `tube between the ends and .sealing the tube at the'cutwith a flat closure,- which comprises a generally horizontal shaft mounted for rotation, a second shaft attached at one end to the first Ashaft and lying parallel to and offset from the first shaft, a clamp for holding a tube extending generallylengthwise of the shafts and with one end projecting beyond the free end of the second shaft, means'for securing the clamp to the Fsecond shaft in different positions of adjustment about an axis normal to that of the'second shaft, burner'means producing a planarameadapted to intersect said pro- 1 jecting en d of the clamped tube, the plane of l the burner means on said mounting to cause the I flame to shift along the clamped tube.

jecting end of the clamped tube, the plane of the flame lying transverse to the axis of the secondy shaft, a mounting for the burner means'on which the burner means may be tilted about an axis offset from and substantially normal to the axis of the second shaft, and means for tilting means for securing the clamp to the second shaft in different positions of adjustment about an axis normal to that of the second shaft, burner means for producing a planar flame adapted to intersect said projecting end of the clamped tube,

the plane of the flame lying transverse to the axis of the second shaft, a mounting for the burner means on which the burner means may be tilted about an axis offset from and substantially normal to the axis of the second shaft, means acting onthe burner means and tending whom said means with the name in en initial position, and means for tilting the burner means to shift the flame to a second position.

5. An apparatus for cutting a glass tube between its ends and sealing the tube at the cut with a flat closure, which comprises a generally horizontal' shaft mounted for rotation, a second shaft attached at one end to the first shaft and lying 'parallel to and offset from the first shaft, a clamp the flame lying transverse' to the axis-of the second shaft, and means for 'moving the burner means to a limited extent to shift the planar'fiame along the clamped tube.

"for holding a tube extending generally lengthwise of the shafts and with one end projecting beyond'the free end of the second shaft, means for securing the clamp to the second shaft in v2. An apparatusfor cutting a'glas'stube b e A l'tween its ends'andsealing the .tube vat-the cut with a fiat closure, whichcomprises a generally horizontal shaft mounted for rotation; a `second shaft attached'at'zone'end to thefirst shaft and lyingv parallel to and offsetlfrom the first shaft, a

different positions of adjustment about an axis y normal to that of the second'shaft, a pair of clamp' including holdingelements for-holding a tube extending generally lengthwise o f the shafts v jand with.one end `projecting beyond thej free end of the second. shaft, means for securing the through the axis of the shafts, the clamp being adjustable "to different positions about an axis normal to that of the second' shaft, burner'means producing a planar flame adapted to intersect said projecting end of the clamped tube, the plane of the` flame lying transverse .to thel axis of the second vshaft, andmea-nsformoving the burner burners secured together and producing flames merging to form a planar flame, the plane of whichintersects said projecting end of theA clamped tubeand lies transverse to the axis of the second shaft, a mounting for said burners on whichthey may be tilted about an axis offset -clampv to the second shaftwith' the holding ele- 1 ments extending substantially parallel to a plane from and normal to the axis of the second shaft, a spring acting on the connected burners and tending to hold them in one position, and means connected-to the burners and operable to swing them to a second position against the action of said s'pring.

6. A n apparatus for cutting a glass tube between its ends and lsealing the tube at the cut with a nat closure, which comprises a generally horizontal shaft mounted for rotation on bearmeans to a limited extent toshift the planar` a nat closure, whiclr-comp'riscs'a generallyhorp z ontal shaft mounted for-rotation, a second shaft -attached at .one end to fthe' first shaftfand :lying parallel to and offset from 'the first shaft, a clamp" for holding a tube extending generallyilengthwise,

' of the shafts and with one .end projecting beyond the free en'd of the second shaft, means for se# vcuring the clamp to-the second shaft in different vpositions of adjustment about` an axis normal to that of the` second shaft.' burner means' for pro- Yducing. a planar name .intersecting said Proings, a crank arm at one end of the shaft, a second' shaft mounted at one end in the free end of the arm and lying parallel to the first shaft, a clamp for holding a tube extending generally lengthwise of the shafts and with one end projecting beyond the free end of the second shaft,

means for securing the clamp to the free end of the second shaft for adjustment to different positions about an axis normal to that' of the second shaft, a pair of burners connected together and producing flames merging into a planar flame adapted to intersect said end of the clamped tube, and a mounting on which the. .burners are' tiltable about an axis offset from and normal to the axis of the second shaft.

O. LUERTZING. 

